The present invention relates to an image forming apparatus having a blade member for removing toner remaining on a surface of a toner supporting member.
In a conventional image forming apparatus for forming an image through a photoelectric method such as a printer, a copier, a fax machine, and a multifunction product thereof, an LED (Light Emitting Diode) head exposes a surface of a photosensitive drum to form a static latent image. A developing device develops the static latent image to form a toner image, and a transfer device transfers the toner image to a sheet. A fixing device fixes the toner image on the sheet, thereby forming an image. After the toner image is transferred, a blade or a cleaning device removes toner remaining on the surface of the photosensitive drum.
In the conventional image forming apparatus, a transportation belt or a toner supporting member for transporting the sheet is disposed to contact with the photosensitive drum. Accordingly, toner adheres also to a surface of the transportation belt, and the blade or the cleaning device removes toner remaining on the surface of the transportation belt as well. In this case, the blade abuts against the surface of the transportation belt or the toner supporting member to scrape off toner, thereby cleaning the surface of the toner supporting member (refer to Patent Reference).    Patent Reference; Japanese Patent Publication No. 2004-77607
In the conventional image forming apparatus, when an image is continuously formed, a contact portion of the blade abutting against the surface of the toner supporting member may be curled up. FIG. 2 is a view showing a blade of a conventional image forming apparatus.
As shown in FIG. 2, a blade 202 abuts against a surface of a transportation belt 201. A sheet is placed on an area 203 of the transportation belt 201. In a printing operation, toner adheres to the area 203 of the transportation belt 201 in a different manner from that in other areas where the sheet is not placed. Accordingly, the blade 202 slides against the transportation belt 201 at a boundary between the area 203 and the other area in significantly different conditions. As a result, when the printing operation is performed continuously on sheets having a same size, portions 205 of the blade 202 abutting against side edges of the sheet 203 on the transportation belt 201 tend to be curled up.
In view of the problems described above, an object of the invention is to provide an image forming apparatus capable of preventing a blade member from being curled up. In the image forming apparatus, a blade member is provided for removing toner remaining on a toner supporting member, and a toner retaining member is disposed on a upstream side of the blade member in a transportation direction for retaining toner remaining on the toner supporting member. Accordingly, it is possible to stably supply toner to a portion of the toner supporting member contacting with the blade member, thereby stabilizing a friction load between the toner supporting member contacting with the blade member.
Further objects and advantages of the invention will be apparent from the following description of the invention.